The field of the invention is an automatic release mechanism, and the invention relates more particularly to a water activated automatic release mechanism for a parachute harness.
U.S. Pat. No. 5,857,247 issued Jan. 12, 1999, for “Buckle System for Manual or Automatic Release of Crew Member Harness from Parachute” and assigned to the assignee of the present application, discloses a buckle system having many of the features of the present invention. The '247 patent is incorporated herein by reference for background purposes.
Combat aircraft often operate over water, and due to the role of such aircraft, crew members may experience a need to parachute from the aircraft. Such need may result from hostile fire in combat, from an accident, or due to equipment failure. The crew members may further experience injury prior to exiting the aircraft, during the exiting, or after the exiting. In some cases, a crew member may land in water in an unconscious or disabled condition. If the crew member should land in water, and is unable to release their parachute, the added weight and/or drag may pull the crew member below the water surface, and may result in further injury or drowning.
To prevent such further injury or drowning, known parachute harnesses include an automatic release mechanism. Such release mechanism includes at least two critical requirements. First, that the mechanism has a high probability of correctly releasing the parachute if the crew member becomes immersed in water. Second, a near zero probability of false release. Generally, the crew member will be able to release the parachute, and therefore a failure of the automatic release mechanism to perform a correct release is generally not a critical event. Alternatively, a false release may be a fatal event.
The '247 patent teaches such release mechanism integrated internally into a buckle of the parachute harness. Although the release mechanism of the '247 patent provides the needed automatic release functionality, the release mechanism is not easily removed from the buckle for service, battery replacement, or to upgrade to a new release mechanism. Further, a new buckle system has been developed which requires a new automatic release mechanism. What is needed is an automatic release mechanism for the new buckle, which new automatic release mechanism may easily be removed for service, battery replacement, or to upgrade with a new release mechanism. Due to the extreme cost of a false release, there is also a need for false release events to have the lowest possible probability, while maintaining a reasonable probability of correct release.